<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="utf-8"/>
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"/>
    <meta name="viewport"
          content="width=device-width, initial-scale=1, maximum-scale=1,minimum-scale=1, user-scalable=no">
    <title>bg</title>
    <link rel="shortcut icon" href="../img/logo.png" type="image/x-icon"/>
    <link rel="stylesheet" href="../css/bootstrap.css">
    <script src="../js/html5shiv.js"></script>
    <script src="../js/respondjs.js"></script>
    <script src="../js/popper.js"></script>
    <script src="../js/jquery-3.4.1.js"></script>
    <script src="../js/bootstrap.js"></script>

</head>
<body>
<div class="container">
    <!-- 按钮组 -->
    <div class="btn-group">
        <button type="button" class="btn btn-primary">btn1</button>
        <button type="button" class="btn btn-info">btn2</button>
        <button type="button" class="btn btn-danger">btn3</button>
    </div>

    <!-- 下拉按钮组 -->
    <div class="btn-group">
        <div class="btn btn-primary dropdown-toggle" data-toggle="dropdown">
            primary<span class="caret"></span>
        </div>
        <ul class="dropdown-menu" role="menu">
            <li><a href="#">功能</a></li>
            <li><a href="#">另一个功能</a></li>
            <li><a href="#">其他</a></li>
            <li class="divider"></li>
            <li><a href="#">分离的链接</a></li>
        </ul>
    </div>

    <form action="" role="form">
        <!-- 左右组合 -->
        <div class="input-group input-group-sm">
            <span class="input-group-addon">@</span>
            <input class="form-control"/>
        </div>
        <!-- 左右组合 -->
        <div class="input-group input-group-sm">
            <input class="form-control"/>
            <span class="input-group-addon">.00</span>
        </div>
        <!-- 左中右组合 -->
        <div class="input-group input-group-sm">
            <span class="input-group-addon">$</span>
            <input class="form-control"/>
            <span class="input-group-addon">.00</span>
        </div>
    </form>
</div>
</body>
</html>
